Various products require time for what is called either “aging” or “drying”. Cheeses and meats have historically been aged in caves. The local climate, geological conditions and season, dictated the temperature and humidity in the caves. Due to these varied conditions, different styles and types of products come from different locations. People are now making aged cheeses and meats of all different types, and in all locations around the world. The challenge they face is controlling/creating the proper conditions in the rooms where the product is being dried or aged. At present most facilities try to control the temperature in the room (dry bulb) and humidity (% RH) with limited success. % Relative Humidity is calculated using the Partial Vapor Pressure (ew)/Saturated Vapor Pressure (e*w)*100. The Saturated Vapor Pressure changes with the Dew Point. The Partial vapor pressure changes with the dry bulb temperature.